Electric Cooling Fan Malfunction

[SVONASH]

This is my first post. I have an ’86 SVO with about 22,800 miles on it. It’s white with gray leather interior. I bought it new in 1986.

Anyway, the electric cooling fan won't come on. (I know, what’s new.)

This is what I have tested and the results:

1. I ran a jumper from the battery to the fan and the fan motor works.

2. I turned on the A/C but the pump won't engage, probably because the system needs charging. I was hoping that would cause the fan to operate but it didn't. So then I jumped the low pressure sensor for the A/C and the compressor engaged but the electric cooling fan still didn't come on.

3. I grounded the cooling fan switch and the fan still didn't function.

4. I turned on the defroster and the fan still didn't come on.

5. I can't see any melted wires to the control module or any apparent damage inside of the control module.

6. I checked for codes with my Snap On scanner and got the following:

A. 67 PNP or clutch switch ckt failure.
B. 61 coolant temp signal low-ckt grounded.


I’m thinking that the problem may be the cooling fan module since I believe it sends and/or receives signals from/to both the A/C and cooling fan switch. The codes I got seem to reflect that.

Any comments are appreciated.

Thanks, Richard

[BrianO]

only three things in the loop.. fan motor, fan switch, and fan module under the dash.

you said you grounded the switch, but if it's bad it won't work. take the wire off that switch and put it to ground. if the fan comes on then the switch is bad and the module under the dash is good. If it does not come on then the module under the dash is bad and/or the switch as well.

of course the wiring on our cars isn't that great either so that is also a concern.

[SVONASH]

you said you grounded the switch, but if it's bad it won't work. take the wire off that switch and put it to ground.

Sorry. I meant I grounded the wire to the switch.

So then that points to the module if my wiring is good.

Thanks!

[Chuck]

Welcome to the forum! Judging by your posting count of 2, I'd say you've never been here before so how about registering your car in the registry? As an original 1986 owner myself (but with more than 24K miles), welcome to the club. Got any pictures to post?

[SVOeric]

Welcome to the forum
If you search for "TRW FAN", you'll find about 40 posts that match up with your problem. Try the search feature, it's your friend. you can probably even find some info on where to get a replacement, or even how some people trash the TRW controller, and go aftermarket.

[SVONASH]

Thanks guys!

Registered the vin no. today.

Yes I have been doing a lot of searching. That's how I knew what to trouble shoot so far. I'm going to try further tests to be sure the controller/relay is bad before I buy a new one.

I disconnected the relay. Can't see any burnt or melted wires or connections. However, the windings on the left are discolored from those on the right. I wonder if that may be the problem.

[SVONASH]

Got my new module/controller today from Autozone and it's the wrong one. It only has one realy and not both. Those guys certainly are in the zone. I'll see if I can dig up the correct number and help them out.

[SVONASH]

For the record, the Ford part number of the bad controller is: E6ZB-8C609-AA

[Meotchh]

Sounds like AZ gave you the unit for a non-AC car.
Have you checked the resistance of the coils in the relays?

http://www.svoca.com/forum/showthread.php?t=17539&highlight=Relay

[Chuck]

I replaced mine from Ford several years ago and the parts guy said that it was a good thing since they had recently incorporated some mods and improved it. Tried the Ford dealer? I always dealt with "Specialty Parts" and Sanderson Ford in Glendale, AZ.

[SVONASH]

Sounds like AZ gave you the unit for a non-AC car.
Have you checked the resistance of the coils in the relays?

The discolored coil is 1.5ohm (fan relay) and the regular copper colored coil is 53.1ohms. Before I noticed I had the wrong relay (I think it's for a power antenna) I installed it and the cooling fan functioned properly.

I replaced mine from Ford several years ago and the parts guy said that it was a good thing since they had recently incorporated some mods and improved it. Tried the Ford dealer? I always dealt with "Specialty Parts" and Sanderson Ford in Glendale, AZ.

I ordered one from Murray's today. If that's the wrong one I'll go to the dealer.

[Meotchh]

If you are good with a soldering iron & solder sucker, just swap the relay on the board out with another from a JY. Low cost & fairly quick to do. The hardest part is searching the yard for another fox body with an electric cooling fan.

[NY eric]

The discolored coil is 1.5ohm (fan relay) and the regular copper colored coil is 53.1ohms. Before I noticed I had the wrong relay (I think it's for a power antenna) I installed it and the cooling fan functioned properly.

I ordered one from Murray's today. If that's the wrong one I'll go to the dealer.

Dealer is not going to have it. Ford marked it for the clearing house a couple of months ago. it also goes by RR-18 from motorcraft.

[BrianO]

Autozone has the correct one.. just FYI

Part Number: MT0683
Weight: 0.25 lbs
Application: With Federal emission With A/C
Notes: Radiator fan control
Operation: Radiator Fan Controller Integrated Control Module
Shipping Information: Overnight and Two Day shipping are not available for PO Box, APO/FPO/DPO or US Territory addresses.

[SVONASH]

Autozone has the correct one.. just FYI

Part Number: MT0683

I look up 86 Mustang SVO and I get a not available part number MR103.

How did you come up with part number MT0683?